With the rapid development of integrated circuit technology, the application of contactless IC card or smart card is becoming more and more widespread, which, in turn, makes data communication more convenient. For example, if a person carries a con-tactless IC card with an induction coil with him, he can conveniently communicate with certain external sensing terminals for ID identification and confirmation, electronic data communication or E-money use on the bus, in the subway, banks, hospitals or membership clubs. However, IC card is easy to get lost, and is not convenient to carry. To solve this problem, some manufacturers have already manufactured watches with smart cards. Some has the smart card soldered on the printed circuit board (PCB board), which has solved the carriage problem, but the function of the watch is limited to the service functions of the smart card soldered inside it in the factory whose function is simple and cannot be repaired conveniently. While some manufactures install the smart card into the watch from the backcover, thus smart cards can be easily replaced.